title: Additional value of dual-energy CT to differentiate between benign and malignant mediastinal tumors: an initial experience.
abstract: OBJECTIVE
  To investigate the feasibility of dual-energy computed tomography (DECT) in differentiating malignant from benign mediastinal tumors.
  
  
  METHODS
  We prospectively enrolled 25 patients (14 males; mean age: 56.7 years) who had suspected mediastinal tumors on chest radiography or non-contrast chest computed tomography (CT). All patients underwent a two-phase DECT using gemstone spectral imaging (GSI) mode (GE HD750). For the quantitative analysis, two investigators measured the following parameters of the tumors in the early and the delayed phases: CT attenuation value in Hounsfield units (HU) and iodine concentration (mg/ml). Pathological results were used for a final diagnosis. Statistical analyses were performed using the Fisher's exact test and the Mann-Whitney t-test.
  
  
  RESULTS
  10 patients (40%) had benign pathology, while 15 (60%) had malignant pathology. The iodine concentration measurements were significantly different between benign and malignant tumors both in the early phase (1.38 mg/ml vs. 2.41 mg/ml, p=0.001) and in the delayed phase (1.52 mg/ml vs. 2.84 mg/ml, p=0.001), while mean attenuation values were not significantly different in both phases (57.8 HU vs. 69.1 HU, p=0.067 and 67.4 HU vs. 78.4 HU, p=0.086, respectively).
  
  
  CONCLUSIONS
  Dual-energy CT using a quantitative analytic methodology can be used to differentiate between benign and malignant mediastinal tumors.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, 120-752 Seoul, Republic of Korea. Electronic address: circle1128@yuhs.ac.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Jin
authors.initials: J
authors.lastname: Hur
authors.forename: Young Jin
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hye-Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Yoo Jin
authors.initials: YJ
authors.lastname: Hong
authors.forename: Byoung Wook
authors.initials: BW
authors.lastname: Choi
mesh_terms: D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010865:Pilot Projects; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Benign neoplasm; Differentiation; Dual-energy computed tomography; Malignant neoplasm; Mediastinal neoplasms